Treatment of coniferous woods.



nerous Woodmof which theollowng.

'Eo viewing To all wko/m, Iii may some/m eizexe of :ho United States,ces ng D'eLxroiV in the countyo Weyhe ou .St'ate of Michigan, have invene certain new; alii useful mprovements in, reaneot of Co e specicatom.

This inventlon releteso the'heieuiffof eomff-:rous woods. the obgect of the mventwo beleg the provslon oit -aneeonomlg and' eifeeive mehod O treating auch Woof the recovery o Vaoable proucts-apd `the prepemtlon of e, stock or ehlp s ixsceptlbleo quahty.

in older to prepare from coniferouswoos e pure cellulose ber suitablefor themanutesine en oewreeins( Aeeeidng ,temfyl vennen the removal of these 1s effected 'by the solvent action of a voletlefsolven, ob;

1eine in speeo viLjy, boiling point, gol' and other lmportent eheracjte ties, and bemgat present of unknown ehemf ief eonstltution'although probeblycolitigly of the] ing one oe more iz'ercpenes"n The eeton eovent may be preeede; orlfo by-Ais1 Wooe m e poroxs comlmon Whchvmclhtates the paneel-amen or permeatxon of the pulp.

Honors; shorten?, Vernon' migo pulp,

eocky sueh es cereut varieties of Conifer-, oue- 'woods of high 'oil and resin conent.

' e eid ,reaetion to a residue l fl 0 60 cluding repeated treatments with successive l otherwise rapid extraction'of the resins and oily matters of the wood. In practice I prefer to heat the solvent to such degree-.that-it distils` slowly from the digester, thus insuring suiiicient circulation of the liquid in and among the chips. lt is advisable but not necessary to maintainwithin the digester during this extraction a' pressure 'somewhat below atmospheric. p,

In order to remove completely the oils and rcsinous matters the extraction should be continued with fresh portions of the volatile' solvent, such portions being introduced hot, in order that the 4melted resins of the wood l'i'iay not become chilled' or solidified and thereby rendered more difficult of extraction.

After the soluble constituents of the wood A have been completely extracted the vliquid contents of the digester are drawn off and the wood chips are then steamed to remove and recover the remaining solventr The enriched solvent from the dlgesters is fractionally' distilled, whereby the volatile solvent is recovered and in addition thereto the following fraetions: a wood turpentine, b wood oils, socalled, varying in specific gravity from .870 to'.J40 and c residue-resin,

ln fractionating as above a vacuum corresponding to about 20-25 inches` of mercury is preferably used, closed heating coils being employed for distillin -the volatileu solvent, wood turpentine an the .lighter wood oils, and closed coils and live steam for the heavier wood oils.

'The exhausted chi s remaining in gester are then rea y to receive thepulp li uors, which may comprise either caustic s a or bisulfite solutions asis well understood in the art. If desired the chips may be subjected before introduction of the pulp liquors to the action of diminished pressure to remove solvent.

vInstead of directly to the action of the volatile solvent as described above the process may be modified as follows: The elnps are placed in the digester as before, and are subjecte to. the actionV of slightly traces of extractiva matter and whereby the volatile solvent havngfa spei l substantially .as

cific rrravity lower than that of commercial oil of tur entine is distilled over andcollected as a ove described.y The collected `solvent from this or previous o erations, or the lighter fraction thereof, is t en returned to the di ester to submerge the partially exhauste chips therein and to complete the extraction, the conditions of operation, in-

portions of the solvent, -being preferabl have been dcscrlbed. wit

reference to the direct treatment of raw toa temperature suitable for the 'the disubmitting the coniferous wood superheated4 stea for a limited period, preferably about two-hours,

chips with the solvent. The subsequent 0perations, including the conversion of the exhausted chips into -fiber stock, follow substantially in the manner described above.

I claim: y

1. 'Ihe process whichv consists in subject extracting soluble constituentsl of conifcrous wood with said volatile solvent.

3. The process which consists in subject ingk a coniferous wood todistillation to obtain a volatile solvent having ay lower specific lgravity and boiling point than commercial oil of turpentine,` extracting soluble constituents of coniferous wood with said volatile solvent, and finally converting the ex.

traeted wood into pulp or Afiber stock.

4. The process which consists in subject'.- ing a coniferous wood to limited distillation with steam to obtain a volatile solvent having a lower specific gravity and boiling` point than commercial oil ot' turpentine, extracting soluble constituents of coniferous wood with said volatile solvent, and finally converting the extracted wood into pulp 0r fiber stock. y

5. The process which consists in subjecting axconlferous wood to distillation with steam yto obtain a volatile solvent, and then extracting soluble constituents from the partially exhausted wood with said solvent.

6. The process which consists in subjecting'a coniferous wood to limited distillation with steam to obtain arvolatilc solventJl having a lower specific gravity and boiling point than commercial oil of turpentine, and then extracting soluble constituents from the partially exhausted wood with said solvent.

7. The process which consists in subject* inga coniferous wood te distillation with steam to obtain a volatile solvent, extracting soluble constituents fromv the partially exhausted wood with said solvent, and finally converting the extracted wood into pulp or fiber stock.

B. The recess which consists in subject ing a coniferous wood to distillation to ohtain a volatile solvent and subjecting coniferous wood to repeated extractions with successive portions of said solvent.

9. The-process which consists in subjectinfr a coniferous wood to distillation to ohtain a volatile solvent, subjecting coniferous wood to repeated extractions with successive ist portions of said solvent, and iinally convert-- ing a coniferons Wood to limited distillation with steam to obtain n volatile solvent havinga lower` specific gravity end boiling point than'commerclal oil of turpentine, and then N subjecting the partially exhausted Wood to repeated extractions with successive portions of said solvent.

11. The process which consists in subjectin a coniferous wood to limited distillation Wi h steam to obtain a volatile solvent l'ntving a lower specific gravity and boiling point than comxnerclal oil of turpentine, subjecting the partially exhausted Wood to repeated extractions with successive portions of seid solvent, and linnlly converting the extracted wood into pulp or ber stock.

12. The process which consists in subjecting n coniferous Wood to distillation to 'ob-.-

tain a volatile solvent having a'lower specitic gravity and boiling point than commercial loil of turpentine, extracting soluble coni stitnents of coniferous Wood wlth sani volti-f tile solvent, and fractioneting the enriched I' solvent.

13. The process which consists in subjecting a coniferous wood to distillation to obtain a volatile solvent linvingfa lower specific gravity and boiling point than commercial oil oi' turpentine, extracting soluble constituents of oniferous wood withsaid volatile solvent, fractionnting the enriched solvent, and finally converting the extracted wood into pulp or iber stock.

ntestilnony whereof, I niiix my signature in presence of tivo Witnesses.

WILLsoN H. ROWLEY.

' Witnesses:

WILLIAM J.GRAY, JAS. J. McINTYnn. 

